Submission #53847398

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Source Code Expand

# ojp

import sys
# sys.setrecursionlimit((1<<30)-1)
# from math import gcd, lcm
# from copy import deepcopy
# from collections import deque
# from collections import defaultdict
# from collections import Counter
# import bisect
# import numpy as np
# import atcoder as ac
# from atcoder.segtree import SegTree
# from atcoder.lazysegtree import LazySegTree
# from atcoder.fenwicktree import FenwickTree
# ???from heapq import heappop, heappush
input = lambda: sys.stdin.readline().rstrip()
_m = lambda type=int: map(type, input().split())
_l = lambda type=int: list(_m(type=type))
_mtx = lambda x, type=int: [_l(type=type) for _ in range(x)]
INF=10 ** 18

ans = 0
# n = int(input())
n,t = _m()
a = _l()
# a = list(input())
# a = _mtx(n)

row=[n]*n
col=[n]*n
nan1=n
nan2=n

for i in range(t):
    ai=a[i]
    ai-=1
    h=ai//n
    w=ai%n
    row[h]-=1
    col[w]-=1
    if h==w:
        nan1-=1
    if h+w==n-1:
        nan2-=1

    if row[h]==0 or col[w]==0 or nan1==0 or nan2==0:
        print(i+1)
        exit()

print(-1)

Submission Info

Judge Result